Chapter 25: Electric Current and Direct Current Circuits

1
Chapter 25 Electric Current and Direct Current
Circuits
2
If 4.7 1016 electrons pass a particular point
in a wire every second, what is the current in
the wire?

1. 4.7 mA
2. 7.5 A
3. 2.9 A
4. 7.5 mA
5. 0.29 A

3
If 4.7 1016 electrons pass a particular point
in a wire every second, what is the current in
the wire?

1. 4.7 mA
2. 7.5 A
3. 2.9 A
4. 7.5 mA
5. 0.29 A

4
The graph shows the potential difference across a
resistor as a function of the current through the
resistor. The slope of the resulting curve
represents

1. power.
2. resistance.
3. emf.
4. charge.
5. work per unit charge.

5
The graph shows the potential difference across a
resistor as a function of the current through the
resistor. The slope of the resulting curve
represents

1. power.
2. resistance.
3. emf.
4. charge.
5. work per unit charge.

6
A resistor carries a current I. The power
dissipated in the resistor is P. What is the
power dissipated if the same resistor carries
current 3I?

1. P
2. 3P
3. P/3
4. 9P
5. P/9

7
A resistor carries a current I. The power
dissipated in the resistor is P. What is the
power dissipated if the same resistor carries
current 3I?

1. P
2. 3P
3. P/3
4. 9P
5. P/9

8
The power dissipated in each of two resistors is
the same. The potential drop across resistor A
is twice that across resistor B. If the
resistance of resistor B is R, what is the
resistance of A?

1. R
2. 2R
3. R/2
4. 4R
5. R/4

9
The power dissipated in each of two resistors is
the same. The potential drop across resistor A
is twice that across resistor B. If the
resistance of resistor B is R, what is the
resistance of A?

1. R
2. 2R
3. R/2
4. 4R
5. R/4

10
Two resistors are connected in series across a
potential difference. If the current carried by
resistor A is I, what is the current carried by
B?

1. I
2. 2I
3. I/2
4. 4I
5. impossible to determine unless more is known
   about the resistances of A and B

11
Two resistors are connected in series across a
potential difference. If the current carried by
resistor A is I, what is the current carried by
B?

1. I
2. 2I
3. I/2
4. 4I
5. impossible to determine unless more is known
   about the resistances of A and B

12
Four identical light bulbs are connected to a
power supply as shown. Which light bulb consumes
the most power?

1. B1
2. B2
3. B3
4. B4
5. They all consume the same amount of power.

13
Four identical light bulbs are connected to a
power supply as shown. Which light bulb consumes
the most power?

1. B1
2. B2
3. B3
4. B4
5. They all consume the same amount of power.

14
Four identical light bulbs are connected to a
power supply as shown. Which light bulb consumes
the most power?

1. B1
2. B2
3. B3
4. B4
5. They all consume the same amount of power.

15
Four identical light bulbs are connected to a
power supply as shown. Which light bulb consumes
the most power?

1. B1
2. B2
3. B3
4. B4
5. They all consume the same amount of power.

16
If two elements of a circuit are in parallel,
they must have the same

1. charge.
2. potential difference across them.
3. resistance.
4. potential difference across them and the same
   current.
5. current.

17
If two elements of a circuit are in parallel,
they must have the same

1. charge.
2. potential difference across them.
3. resistance.
4. potential difference across them and the same
   current.
5. current.

18
Which of the following relations among the
quantities in the figure is generally correct?

1. I1R1 I2R2
2. I3R3 I4R4
3. I1R1 I4R4
4. I3R4 I4R3
5. I1R1 I2R2 e

19
Which of the following relations among the
quantities in the figure is generally correct?

1. I1R1 I2R2
2. I3R3 I4R4
3. I1R1 I4R4
4. I3R4 I4R3
5. I1R1 I2R2 e

20
Three resistors are placed in a simple circuit.
In which of the various configurations shown do
all three resistors carry the same current?
21
Three resistors are placed in a simple circuit.
In which of the various configurations shown do
all three resistors carry the same current?
22
The power delivered by the battery in the circuit
shown is

1. 2.5 W
2. 7.0 W
3. 3.1 W
4. 9.7 W
5. 5.3 W

23
The power delivered by the battery in the circuit
shown is

1. 2.5 W
2. 7.0 W
3. 3.1 W
4. 9.7 W
5. 5.3 W

24
Capacitance
25
A capacitor of capacitance C holds a charge Q
when the potential difference across the plates
is V. If the charge Q on the plates is doubled
to 2Q,

1. the capacitance becomes (1/2)V.
2. the capacitance becomes 2C.
3. the potential changes to (1/2)V.
4. the potential changes to 2V.
5. the potential does not change.

26
A capacitor of capacitance C holds a charge Q
when the potential difference across the plates
is V. If the charge Q on the plates is doubled
to 2Q,

1. the capacitance becomes (1/2)V.
2. the capacitance becomes 2C.
3. the potential changes to (1/2)V.
4. the potential changes to 2V.
5. the potential does not change.

27
If a capacitor of capacitance 2.0 µF is given a
charge of 1.0 mC, the potential difference across
the capacitor is

1. 0.50 kV.
2. 2.0 V.
3. 2.0 µV.
4. 0.50 V.
5. None of these is correct.

28
If a capacitor of capacitance 2.0 µF is given a
charge of 1.0 mC, the potential difference across
the capacitor is

1. 0.50 kV.
2. 2.0 V.
3. 2.0 µV.
4. 0.50 V.
5. None of these is correct.

29
An 80-nF capacitor is charged to a potential of
500 V. How much charge accumulates on each plate
of the capacitor?

1. 4.0 104 C
2. 4.0 105 C
3. 4.0 1010 C
4. 1.6 1010 C
5. 1.6 107 C

30
An 80-nF capacitor is charged to a potential of
500 V. How much charge accumulates on each plate
of the capacitor?

1. 4.0 104 C
2. 4.0 105 C
3. 4.0 1010 C
4. 1.6 1010 C
5. 1.6 107 C

31
Doubling the potential difference across a
capacitor

1. doubles its capacitance.
2. halves its capacitance.
3. quadruples the charge stored on the capacitor.
4. halves the charge stored on the capacitor.
5. does not change the capacitance of the capacitor.

32
Doubling the potential difference across a
capacitor

1. doubles its capacitance.
2. halves its capacitance.
3. quadruples the charge stored on the capacitor.
4. halves the charge stored on the capacitor.
5. does not change the capacitance of the capacitor.

33
Several different capacitors are hooked across a
DC battery in parallel. The charge on each
capacitor is

1. directly proportional to its capacitance.
2. inversely proportional to its capacitance.
3. independent of its capacitance.

34
Several different capacitors are hooked across a
DC battery in parallel. The charge on each
capacitor is

1. directly proportional to its capacitance.
2. inversely proportional to its capacitance.
3. independent of its capacitance.

35
Several different capacitors are hooked across a
DC battery in parallel. The voltage across each
capacitor is

1. directly proportional to its capacitance.
2. inversely proportional to its capacitance.
3. independent of its capacitance.

36
Several different capacitors are hooked across a
DC battery in parallel. The voltage across each
capacitor is

1. directly proportional to its capacitance.
2. inversely proportional to its capacitance.
3. independent of its capacitance.

37
Several different capacitors are hooked across a
DC battery in series. The charge on each
capacitor is

1. directly proportional to its capacitance.
2. inversely proportional to its capacitance.
3. independent of its capacitance.

38
Several different capacitors are hooked across a
DC battery in series. The charge on each
capacitor is

1. directly proportional to its capacitance.
2. inversely proportional to its capacitance.
3. independent of its capacitance.

39
Several different capacitors are hooked across a
DC battery in series. The voltage across each
capacitor is

1. directly proportional to its capacitance.
2. inversely proportional to its capacitance.
3. independent of its capacitance.

40
Several different capacitors are hooked across a
DC battery in series. The voltage across each
capacitor is

1. directly proportional to its capacitance.
2. inversely proportional to its capacitance.
3. independent of its capacitance.